Intrapartum fetal vibratory acoustic stimulation during spontaneous and induced states of low activity and low heart rate variability
Zimmer, E.Z.; Vadasz, A.; Reem, Z.
Journal of Reproductive Medicine 35(3): 250-255
1990
ISSN/ISBN: 0024-7758 PMID: 2325037 Document Number: 365154
Fetal response to vibratory acoustic stimulation (VAS) was studied in 12 healthy parturients in the active phase of labor. All fetuses were evaluated in both spontaneous and analgesia-induced states of low activity and low cardiac beat-to-beat variability. Analgesia was induced with intravenous maternal administration of meperidine, 0.8 mg/kg, plus a fixed dose of promethazine (25 mg). The vibratory acoustic stimulus was applied ten minutes after the start of a fetal quiet state, and ten minutes of fetal behaviour was observed after application of the stimulus. The number and mean duration of fetal body movements in the unmedicated fetuses were statistically significantly higher than in the medicated group. Similarly, the number of fetal heart rate accelerations was significantly higher in the unmedicated fetuses than in the medicated ones. Ten minutes after VAS no fetus in the unmedicated group was in a quiet behavioural state, while 10 of 12 medicated fetuses (83%) returned to a quiet state.